In general, various lighting apparatus are installed in crash pads, door trims, and the like of clusters for enhancing recognizability of divers when night-driving time.
For example, clusters for providing driving information through characters or figures of vehicles or engines are formed in front of driver's seats. These clusters include dash boards including graduation, character, and guidelines and lighting apparatus for recognizing these information. In order to prevent glaring caused by direct lighting apparatus, indirect lighting apparatus has been embodied between dials and windows.
In addition, speaker embedded mood lamps of vehicle doors include lighting means, which indirectly lights interior of vehicles. Like this, indirect lighting means have been more installed variously in comparison with direct lighting means.
However, these conventional illumination lights have disadvantage of low flexibility of Back Light Unit (BLU) due to PMMA material thereof having 1 mm or more thickness. Also, in the event that illumination units are installed in a large area, it is impossible for them to have flexibility since they should have light sources at four sides.
Therefore, a method all-in-one surface light devices for manufacturing surface lights having high efficiency and a thickness being 1 mm and less is provided.